Apparatus for assisting discharge of particulate solids from a bin

ABSTRACT

This disclosure teaches a device to assist in discharging (under gravity flow) particulate solids from a bin. A hollow body is positioned in the bin in the vicinity of a gravity discharge outlet thereof. The volume of the hollow body is varied pneumatically, hydraulically and/or mechanically to assist in discharging the solids. By this teaching chimney flow and bridging are obviated. Where the volume of the hollow body is varied pneumatically, air or some other gas may be emitted from the hollow body at the discharge outlet further to assist the discharging of the solids.

United States Patent Lieckfeld .Sept. 3', 1974 APPARATUS FOR ASSISTING DISCHARGE 3,337,094 8/1967 0F PARTICULATE SOLIDS FROM A BIN 315871936 6/ Rim 75] Inventor Werner Lieckfeld Hitzhusen 3,645,583 2/l972 Heath 222/195 Germany FOREIGN PATENTS OR APPLICATIONS 964,940 5 1957 G 222 I95 [73] Assigneez Bran & Luble, Hamburg, Germany y I [22] Fil d; O t, 4, 1972 Primary ExaminerStanley H. Tollberg Assistant Examiner-Larry H. Martin [21] Appl' 292368 Attorney, Agent, or Firm-Erich M. H. Radde [30] Foreign Application Priority Data ABSTRACT 061. 4, 1911 Germany 2149476 This disclosure teaches a device to assist in discharging under gravity flow) particulate solids from a bin. [52] U.S. Cl. 222/193, 222/196 A ll w dy is positioned in th in in th vi inity [51] Int. Cl. B65g 3/12 a gra ity dis harge outlet thereof. The volume of [5 8] Field of Search. 222/193, 195, 196, 202, the hollow y i v ri pneumatically, hydraulically 222/203; 359/DIG. l7, 4, 18, 36, 99; 302/29, and/0r mechanically to assist in discharging the-solids.

56; 214/17 R, 17 D, 17 A By this teaching chimney flow and bridging are obviated. Where the volume of the hollow body is varied [56] References Cited pneumatically, air or some other gas may be emitted UNITED STATES PATENTS from the hollow body at the discharge outlet further to 2,646,905 7 1953 Vincent 222 203 x assist the discha'gmg of the wlids 2,889,963 6/1959 Johnson 222 203 x 9 Claims, 2 Drawing Figures I I i 1 I I I I I I I I f I i J/ I i 2 I I I I I T/ME SEQUENCE FL u/b sup/ 2 r I 1 Pa e? \5 604/ Tea LLED CUUAITEEWEIGHT APPARATUS FOR ASSISTING DISCHARGE OF PARTICULATE SOLIDS FROM A BIN BACKGROUND OF THE INVENTION gion around the axis of the bin. This phenomenon of chimney flow frequently results in disadvantages, be-

cause the material can age or spoil and frequently can be removed from the bin only at high expense. In addition to this, a separating of the material can take place. Also, it'is difiicult to empty thebin completely when it is desired to change the material to be contained therein. When a tendency of the particlesto adhere to each other is great, bridging can even take place, thus entirely preventing the materials from flowing out of the bin.

Various efforts have been made to solve these problems which occur in connection with discharging of particulate solid materials from bins. Thus discharge devices which operate in accordance with vibratory principles have been developed. These vibratory devices, however, require considerable mechanical equipment (particularly if a corrosion-proof design is desired). Furthermore, considerable additional dynamic forces may also be imparted to supporting structures as a result of which the costs of erection and entire units are made considerably more expensive. In ad dition, as a result of the vibrations, there arises the possibility that in the case of certain materials a counterproductive result can occur namely compacting of the particulate solid material with the consequence that the problems already discussed hereinabove are aggravated further.

It has been attempted also to solve these problems by ventilating discharge outlets in .connection with which large quantities of air are blown into the bottoms of the bins so as to bring the particulate solids stored therein into a fluidized condition and thus facilitate their discharge. However, a considerable expenditure of energy is required to blow in the large quantities of air necessary for this purpose. Furthermore, unless extremely expensive air drying systems are provided, there can be introduced into the particulate solid material quantities of moisture which can lead to spoiling of sensitive stored material and, particularly in the case of hydroscopic materials, to sticking together or agglomerating of the particulate solids.

There are also known mechanical discharge devices such as worms, rotatingreamers and the like. Such mechanical devices are, however, exposed to considerable wear. Manufacture of these devices is extremely costly, particularly when they must be corrosion-proof.

SUMMARY OF THE INVENTION The present invention has solved the foregoing problems of discharging particulate solids from a bin by a facile, useful, novel and unobvious approach. A hollow body is positioned in the bin in the vicinity of a gravity discharge outlet thereof. The volume of the hollow body is varied pneumatically, hydraulically and/or mechanically to assist in the discharge of the solids. Where the volume of the hollow body is varied pneumatically, air (or some other gas) may be emitted from the hollow body at the discharge outlet further to assist thedischarging of the solids.

Accordingly one object of the present invention is to provide a discharge device which eliminates the aforementioned disadvantages and permits uniform discharge of particulate solids from the bin.

A further object of the invention is to provide a discharge device capable of being produced without excessive cost and which is usable in corrosion-proof applications as well as in applications which are compatible with foodstuffs.

In accordance with this invention, in for example a vertical cylindrical bin having a frusto-conic al discharge funnel, the foregoing objectives are achieved by providing on the axis of the cone of the discharge funnel (in the vicinity of the outlet opening) an elastic hollow body the volume of which can be varied pneumatically, hydraulically and/or mechanically. Bore holes or nozzles can be arranged in this connection in the circumference of the discharge device. The flexible hollow body is firmly connected with the discharge cone of the bin preferably via pipes. The pipes preferably serve at the same time for feeding and/or exhausting of a pneumatic gas or an hydraulic fluid. The movements in the discharge device are preferably produced by pulsing means which operate in accordance with a prearranged time sequence. A plastic coated fabric is desirable for the hollow body.

BRIEF DESCRIPTION OF THE DRAWING One embodiment of the invention will be explained below in further detail with reference to the accompanying drawing in which:

FIG. 1 shows a bin provided with the discharge device in its stretched condition.

FIG. 2 is comparable to FIG. 1 with the discharge device in its inflated condition.

PREFERRED EMBODIMENT A flexible hollow body 1 is connected at its upper end to a rope 2 which is connected over pulleys 3 with weight 4. At its lower end the hollow body 1 is firmly connected via pipes 5 with discharge cone 6 of the bin. The hollow body 1 is continuously pulled by the weight 4 via the rope 2 into its distended or extended shape. The pipes 5 entering the hollow body 1 are connected via a controllable valve means with a compressed-air The elastic hollow body 1 is connected rigidly with the outlet cone 6 by means of one or more of the pipes 5. The upper part of the flexible hollow body 1 is so held by means of the rope 2 (having a counterweight or by spring tension) that hollow body 1 assumes an extended shape in its relaxed or uninflated condition.

, When air is blown into this flexible hollow body 1,

which preferably consists of a coated fabric but may also be made of any flexible material, through the lower connecting pipes 5, hollow body 1 expands and assumes a predetermined shape having greatest possible volume. By this manner of operation, the flexible hollow body 1 counteracts the chimney flow and/or bridging and favors bulk flow in the manner that a uniform lowering of level of the particulate solids in the bin is obtained. This discharging of the particulate solids can be supported and enhanced by the lateral bore holes 7 in the flexible hollow body 1 whereby a part of the air blown into the hollow body 1 enters into the material of the bin through said lateral opening 7 in the immediate vicinity of the outlet. This excess air flows directly against the wall of the cone 6 so that firmly adhered particles are eddied and discharged.

After a certain pulse duration, the air feed is discontinued and the hollow body 1 is pulled back into its stretched shape (as shown in FIG. 1) by a tackle coming from the upper end of the bin. The air present in the hollow body 1 is thereby blown into the discharging particulate solid material. By the intensive changes in shape of the flexible hollow body 1, chimney flow and bridging of the particulate solids are avoided in the cone 6 of the bin. The particulate solids present in the bin are loosened in the immediate vicinity of the outlet so that even in the case of difficult flowing materials a uniform discharge is obtained. The above-described movements of the hollow body can naturally be controlled, as is obvious to those skilled in the art, at desired intervals of time depending upon the material being conveyed.

Furthermore, it is obvious to those skilled in the art that other suitable mechanical or other means, such as for instance a compression spring within the hollow body, can be used for the movement of the hollow body instead of the tackle or in support thereof. The hollow body consists preferably of a fabric coated with plastic or a similar material. However, it can be made of any desired flexible material, such as for instance rubber, plastic or the like.

It will be apparent to those skilled in the art that wide deviations can be made from the foregoing specific embodiment without departing from the main scope of invention set forth in the following claims.

I claim:

1. In combination,

a. a bin having an interior space for storage of loose particulate solids, said bin having a downwardly directed discharge funnel terminating in an outlet opening in flow communication with the interior of said bin,

b. a hollow body of flexible material positioned in said bin relatively adjacent and above said outlet opening, said hollow body being provided with a plurality of openings relatively adjacent the bottom thereof for discharging gas delivered to said body,

0. means adjacent said outletopening for mounting said hollow body adjacent said opening so as to space the same inwardly from the funnel in all positions of volumetric adjustment of said hollow body, and

d. means for intermittently varying the volume of said hollow body thereby loosening the particulate solids in the bin adjacent said outlet openingand assisting the discharge of such solids through said outlet opening, said means for intermittently varying the volume of said hollow body including means for supplying a gas under pressure to said body and means operatively connected to said body for continuously biasing said body upwardly thereby distending said body and discharging the gas supplied to said body through said openings.

2. The combination of claim 1 wherein said means for supplying a gas under pressure to said body comprises an air compressor.

3. The combination of claim 1 wherein said means adjacent said outlet opening for mounting said hollow body comprises at least one rigid pipe fixedly con nected to the bottom of said hollow body and communicating with a source of compressed gas for varying the volume of said hollow body.

4. The combination of claim 1 wherein said means adjacent said outlet opening for mounting said hollow body comprises a plurality of rigid pipes fixedly connected to the bottom of said hollow body and communicating with a source of compressed gas for varying the volume of said hollow body.

5. The combination of claim 1 wherein said means operatively connected to said body for intermittently varying the volume of said hollow body comprises a rope secured to the upper end of said hollow body and extending exteriorly of said bin, and means for continuously pulling the rope thereby to distend said hollow body and thus vary the volume thereof.

6. The combination of claim 5 wherein said pulling means comprises a counterweight exteriorly of said bin.

7. The combination of claim 1 wherein said means operatively connected to said body for continuously biasing said body upwardly comprises a compression spring within said hollow body.

8. The combination of claim 1 wherein said bin is generally cylindrical in form having a lower end terminating in a frusto conical discharge funnel arranged annularly about the axis of said bin, said hollow body being arranged along said axis.

9.'The combination of claim 8 wherein said means for varying the volume of said hollow body includes at least one rigid pipe arranged radially relative to said axis and connected between the discharge funnel and the hollow body for supporting the hollow body, said v rigid pipe connecting the hollow body in flow communication with said means for supplying gas under pressure.

mg UNITED STATES PATENT OFF ICE I CERTIFICATE OF CQRRECTION PatentNoQ 3 ,833 ,151 Dated September 3 1974 Inventox-(g) above-identified patent; 7

It is certified that error appears in the ted as shown below:

and that said Letters Patent are hereby correc Front page, item [73 1 I The name of the assignee should read: Bran Luebbe signed ax 1d sense this 5rd day of December 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN Commissioner of Patents 1 Attesting Officer 

1. In combination, a. a bin having an interior space for storage of loose particulate solids, said bin having a downwardly directed discharge funnel terminating in an outlet opening in flow communication with the interior of said bin, b. a hollow body of flexible material positioned in said bin relatively adjacent and above said outlet opening, said hollow body being provided with a plurality of openings relatively adjacent the bottom thereof for discharging gas delivered to said body, c. means adjacent said outlet opening for mounting said hollow body adjacent said opening so as to space the same inwardly from the funnel in all positions of volumetric adjustment of said hollow body, and d. means for intermittently varying the volume of said hollow body thereby loosening the particulate solids in the bin adjacent said outlet opening and assisting the discharge of such solids through said outlet opening, said means for intermittently varying the volume of said hollow body including means for supplying a gas under pressure to said body and means operatively connected to said body for continuously biasing said body upwardly thereby distending said body and discharging the gas supplied to said body through said openings.
 2. The combination of claim 1 wherein said means for supplying a gas under pressure to said body comprises an air compressor.
 3. The combination of claim 1 wherein said means adjacent said outlet opening for mounting said hollow body comprises at least one rigid pipe fixedly connected to the bottom of said hollow body and communicating with a source of compressed gas for varying the volume of said hollow body.
 4. The combination of claim 1 wherein said means adjacent said outlet opening for mounting said hollow body comprises a plurality of rigid pipes fixedly connected to the bottom of said hollow body and communicating with a source of compressed gas for varying the volume of said hollow body.
 5. The combination of claim 1 wherein said means operaTively connected to said body for intermittently varying the volume of said hollow body comprises a rope secured to the upper end of said hollow body and extending exteriorly of said bin, and means for continuously pulling the rope thereby to distend said hollow body and thus vary the volume thereof.
 6. The combination of claim 5 wherein said pulling means comprises a counterweight exteriorly of said bin.
 7. The combination of claim 1 wherein said means operatively connected to said body for continuously biasing said body upwardly comprises a compression spring within said hollow body.
 8. The combination of claim 1 wherein said bin is generally cylindrical in form having a lower end terminating in a frusto conical discharge funnel arranged annularly about the axis of said bin, said hollow body being arranged along said axis.
 9. The combination of claim 8 wherein said means for varying the volume of said hollow body includes at least one rigid pipe arranged radially relative to said axis and connected between the discharge funnel and the hollow body for supporting the hollow body, said rigid pipe connecting the hollow body in flow communication with said means for supplying gas under pressure. 